Hardening Fixer Needed

Thanks to the great advice from the APUG.org community, I've been developing film at home -- Diafine, Water Stop, and TF-4. The trouble is that it has become quite obvious that I need a hardening fixer; I shoot Arista.EDU 100 and I've noticed lots of damage to the emulsion even after my most gentle handling.

So, can anyone suggest a fixer that 1) doesn't require the use of a hypoclear agent; 2) is relatively odor-free; and 3) incorporates a hardener?

Kodak makes a fixer that has a hardner already in the concentrate i think it is called Kodakfix. They also make a fixer that has two parts, one the hardner the other fixer and one can mix as desired. It is my understanding that any fixer with a hardner will need a hca for decreasing the wash times; which may not be an issue for you.
I am sure someone with more knowledge will chime in about this issue a bit later.

Dan,
Arista.EDU 100 is made in Hungary by Forte. The Forte emulsion is soft and is easily damaged. However, I routinely process Forte sheet and roll films without experiencing emulsion damage. I do not use a hardening fixer.

If you are tube processing EDU sheet film, the emulsion can easily be damaged during insertion and/or removal of the film from the tube.

If you are tray processing, emulsion damage can happen during development and any of the subsequent steps. In either case, adding hardener to the fixer is probably not going to solve the problem. The best corrective action is to improve your film handling techniques. You may need to sacrifice some film by processing with the lights on, in order to determine what is going wrong.

If you are processing Arista.EDU 100 roll film on reels, you should not be having this problem.

Dan,
With regard to Hypo Clearing Agents (HCA) I quote this 1997 posting by Richard Knoppow, followed by a comment of my own.

"Kodak Hypo Clearing Agent and other so called washing aids are the
result of the discovery that sea water was more effective for washing out
hypo than fresh water. This was first noted around the turn of the century
but extensive research was not until WW-II when the problem of washing
photographic materials on ship board or other locations where fresh water
was in short supply became critical.
It would appear that wash aids work mostly by an ion exchange mechanism.
I've never seen a clear explanation of this so cant provide a citation.
Kodak Wash Aid is approximately: Sodium Sulfite, dessicated, 100 gm; Sodium
Bisulfite, 10 gm; Water 1.0 liter. Dilute 1 part stock to 4 parts water
for use. The commercial product will contain the usual chelating agents in
it to deal with hard water.
Kodak HE-1 Hypo Eliminator is works on a different principle. It
converts the residual hypo to Sodium Sulfate which is more soluble. Kodak
has recommended against using hypo eliminator for several years. It can
damage emulsion and may be too effective washing out the hypo. It was
discovered around 1960 that very small residues of hypo actually stabilize
the silver!
I am not sure what advantage Ammonium salt would have over Sodium but
Crabtree et al of Kodak mentions the use of Ammonium Carbonate as a washing
accelerator in an early paper. It was thought at that time that the main
function of the salt was in changing the pH of the gelatin rather than the
more complex one of ion exchange.
----
Richard Knoppow
Los Angeles, Cadickburk@ix.netcom.com

In summary: For fixers that already contain sodium sulfite (and many do), an additional HCA is redundant. If your fixer does not contain sodium sulfite, add about 15 grams per liter (2 teaspoons) to the working strength fixer bath and forget a separate HCA. Tom Hoskinson, 5/31/04

Developer Hardener?

Maybe what you need is a hardening developer?

There are basically two options: Most staining developers have a hardening effect. The other option is LP-GELADUR from LaborPartner. The English version of the website seems to be missing at present. I have never tried it, but there are rumors that it works...

[snipped a lot]
In summary: For fixers that already contain sodium sulfite (and many do), an additional HCA is redundant. If your fixer does not contain sodium sulfite, add about 15 grams per liter (2 teaspoons) to the working strength fixer bath and forget a separate HCA. Tom Hoskinson, 5/31/04

Don't forget that HCA is alkaline whereas a fixer may be acid or alkaline independently from the sulfite and alkaline conditons promote thiocyanate removal. This may be the reasons why alkaline fixers formulated with sulfite do not need HCA. Acid fixers contaning enough sulfite will probably need at least an alkaline afterbath to wash out residual fixer with comparable efficiency. To me it appears to be safer to include HCA as long as you don't know all these variables for sure.

You need water to remove the residual hypo. The hypo removal process from the emulsion is primarily a chemical diffusion process. This is true for both acid and alkaline fixer baths - with and without HCA.

Hardening the emulsion during or prior to development won't help if the film is scratched in handling before development. I should note that I develop with Pyrocat-HD which tans and hardens the emulsion.

Film can be damaged by surface water removal (wiping the film before drying). If this is the case, emulsion hardening may help. An alternative is to use photo-flo (or equivalent) in distilled water for the final rinse and eliminate the wiping.

You need water to remove the residual hypo. The hypo removal process from the emulsion is primarily a chemical diffusion process. This is true for both acid and alkaline fixer baths - with and without HCA.

Tom,

i should have read the thread before stepping on my soapbox: I thought we were talking about paper where things are bit different.